NASA/ADS

Anomalous magnetic properties in Mn(Se, S) system

Abstract

We have carried out detailed structural, magnetic and thermal properties studies of the Mn(Se, S) system. The detailed structural studies using synchrotron X-ray and neutron diffractions on MnSe confirm the coexistence of cubic and hexagonal phases at low temperature, which shows strong thermal hysteresis suggesting the first-order nature of the transition. Based on the temperature-dependent magnetic susceptibility, we confirmed that the substitution of the sulfur element to selenium critically modified the complex magnetism observed in MnSe. It was to our surprise to observe a magnetic anomaly at 16 K way below the antiferromagnetic order that sets at about 160 K in MnS. Our neutron study at low temperature did not reveal any additional magnetic structure below 16 K. However, the specific heat of MnS shows a clear T1.5 temperature dependence below 16 K, suggesting the possible emergence of a weak ferromagnetic order.